fix(ci): use REGISTRY_TOKEN for build-and-push registry login (CAR-1330)

Squashed fix swaps github.token → secrets.REGISTRY_TOKEN at .gitea/workflows/ci.yml:121, matching the proven-green cartsnitch/auth pattern (CAR-1009). Parity fix with uat PR #49 to prevent reintroduction on next dev→uat promotion.

Note: includes 3 absorbed lint/typecheck commits from PR #48 (already merged to dev via #48) to unblock CI on this branch. No app code changes; one-line CI config swap only.

QA: PR #50 approved by @cs_charlie (review id 4616); CI run 3443 lint/typecheck/test all green.
Co-authored-by: Barcode Betty <32+cs_betty@noreply.git.farh.net>
Co-committed-by: Barcode Betty <32+cs_betty@noreply.git.farh.net>

.gitea/workflows/ci.yml

@@ -118,7 +118,7 @@ jobs:
           echo "CalVer tag: $VERSION"
 
       - name: Log in to Gitea Container Registry
-        run: echo "${{ github.token }}" | docker login git.farh.net -u ${{ github.actor }} --password-stdin
+        run: echo "${{ secrets.REGISTRY_TOKEN }}" | docker login git.farh.net -u ${{ github.actor }} --password-stdin
 
       - name: Extract metadata
         id: meta